What I did was get some nice, simple plants, some driftwood, and the rock and artificial waterfall from my old tank, then I arranged the hardscape in a way I liked. After I got it looking nice, I added the plants in ways and numbers that I thought added to the look of both them and the hardscape.
In other words, hardscape first, plants next, no plans at all.
My adventures in keeping Indostomus crocodilus, the crocodile toothpick fish. AKA armored stickleback, paradox fish, and freshwater pipefish. Care is (to the best of my knowledge) exactly the same as Indostomus paradoxus.